1. Field
Embodiments relate to light emitting modules.
2. Background
Light Emitting Diodes (LEDs) are semiconductor devices that transmit and receive signals by converting electrical energy into visible or infrared light using properties of compound semiconductors, or that are used as a light source.
Group III-V nitride semiconductors are receiving attention as a core material of light emitting devices, such as Light Emitting Diodes (LEDs) or Laser Diodes (LDs), owing to physical and chemical properties thereof.
These light emitting diodes exhibit excellent environmental friendliness because they do not contain environmentally harmful substances, such as Mercury (Hg) used in conventional lighting including fluorescent lamps, incandescent lamps, etc., and have advantages of low power consumption and semi-permanent lifespan, etc. Therefore, conventional light sources are being replaced by light emitting diodes.
In general, a light emitting module includes light emitting device packages, and in turn each light emitting device package includes light emitting devices, such as LEDs. The light emitting devices are driven by a drive Integrated Circuit (IC). In this case, the light emitting devices are arranged inside the light emitting device package, whereas the drive IC is arranged outside the light emitting device package. As the drive IC is arranged outside the light emitting device package rather than inside the package, there is a need for a space for installation of the drive IC, which limits diversity in the design of the light emitting module.
In addition, a conventional high-voltage light emitting module includes a plurality of light emitting devices connected to one another in series, switching devices to turn the respective light emitting devices on or off, and a single drive IC to control switching of the switching devices. In this case, the drive IC controls switching of the switching devices based on the level of Alternating Current (AC) drive voltage applied from an external source to turn the plurality of light emitting devices on or off in sequence. When the single drive IC controls driving of all of the light emitting devices as described above, the drive IC must be designed to withstand a maximum of 600 volts. This high withstand voltage of the drive IC increases manufacturing costs.
In addition, such a conventional light emitting module includes Zener diodes as well as light emitting devices, in order to prevent electrostatic discharge of LEDs due to static electricity introduced from an external source. However, Zener diodes are expensive, and addition of processes of mounting Zener diodes increases the number of manufacturing processes of the light emitting module, thus increasing manufacturing costs.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.